Motor-driven knife sharpener



Nov. 16, 1954 Filed NOV. 21, 1951 H. w. LINDSAY ETAL MOTOR-DRIVEN KNIFE SHARPENER 2 Sheets-Sheet 1 /N/EN7UF5 HAROLD W. LINDSAY CLARE J. LlNDSAY NOV. 16, 1954 w, LlNDSAY. T 2,694,275

MOTOR-DRIVEN KNIFE SHARPENER Filed Nov. 21, 1951 2 Sheets-Sheet 2 HAROLD w-. LINDSAY CLARE: .1. LINDSAY ,arru /vas 1; ited States Patent M MOTOR-DRIVEN KNIFE SHARPENER Harold W. Lindsay and Clare J. Lindsay, Porfland, Oreg. Application November 21, 1951, Serial No. 257,482

1 Claim. (Cl. 51-128) This invention relates generally to knife sharpeners and particularly to motor driven knife Sharpeners.

The main object of this invention is to construct a knife sharpener which can be attached to an ordinary power driven kitchen mirror.

The second object is to so construct the sharpener that it will have yielding guides for holding the cutting edge in proper relation to the grinding wheel.

We accomplish these and other objects in the manner set forth in the following specifications as illustrated in the accompanying drawings, in which Fig. 1 is a plan of the device.

Fig. 2 is a front elevation.

Fig. 3 is an end elevation.

Fig. 4 is a perspective view of the front cover plate.

Fig. 5 is a perspective view of one of the spring-urged blade guards.

Fig. 6 is a perspective view of the holding arm.

Fig. 7 is a section taken along the line 7-7 in Fig. 2.

Fig. 8 is a section taken along the line 88 in Fig. 2.

Fig. 9 is a section taken along the line 9-9 in Fig. 1. F Fig. 10 is a section taken along the line ill-10 in Fig. 11 is a perspective view of the main body of the device.

Like numbers of reference refer to the same or similar parts throughout the several views.

Referring in detail to the drawings, there is shown in Fig. 11 a detail view of the main body 20 comprised of a bottom 21 having a front wall 22, the rear wall 23 and side walls 24 and 25. A partition wall 26 is formed near the end wall 25. Flanged bushings 27 are mounted in the walls 25 and 26 and serve as journals for a spindle 28 on the outer end of whichis a spring driving connection 29 by means of which the spindle 28 may be driven from any standard food mixer 30.

The longitudinal position of the spindle 28 is fixed by the collar 31 which is held in place on the spindle 23 between the bushings 27 by a setscrew 32. On the outer end of the spindle 28 is mounted a grinding wheel 33 whose sides 34 have the chamfered grinding faces 35.

The inner side 36 of the front 22 is cut away along the arcuate face 37 to provide clearance for the grinding wheel 33. A cap 38 is placed over the body 20 and forms a guard 39 for the wheel 33 and is held down upon the body 20 and bushings 27 by the screws 40. The guard 39 has the sides 41 of its forward end 42 cut away to expose portions of the wheel faces 34.

The top face 43 of the cap 38 slopes downwardly toward the front 22 and has formed along the length thereof a ridge 44, through which are cut the converging knife slots 45 and 46, in either of which may be placed the blade 47 of the knife being sharpened.

The faces 48 and 49 of the slots 45 and 46 are inclined from a vertical plane. The angularity of the slots 45 and 46 and their inclination from the vertical is such as to provide the proper contact between the blade 47 and the grinding faces 34.

Against the front 22 is placed a cover plate 50 (Fig. 4) having a spacing shoulder 51 formed along the bottom Cir 2,694,275 Patented Nov. 16, 1954 thereof, through which extend the fastening screws 52 into the holes 53 in the front 22.

Pins 54 project from the plate 50 and form pivots for the blade guards 55 whose faces 55-A support the knife blade 47 and hold it against the wheel 33. The plate 50 also has a centering pin 56 for which half-round notches 57 are provided along the edges 58 of the blade guards 55. Spring posts 59 are provided on the guards 55 and are connected by a tension spring 60 which urges the parts 55 toward the central pin 56. The plate 50 has a recess 61 formed therein for the spring 60.

The front plate 50 has the upwardly projecting ends 62 whose innermost sides 63 are inclined to conform to the maximum angle of slope at which a blade would be held. The guards 55 are free to swing behind the ends 62 of the front 50.

Against the end 25 is secured the holding arm 64 by means of a screw 65 which passes through the hole 66 into the body 20. The arm 64 has a half-round notch 67 in one end which engages the hub 67-A formed around the spindle 28. A rod 68 extends from the opposite end of the arm 64 and extends into an opening provided therefor in the frame of the mixer 30. The purpose of the arm 64 is to hold the device against rotation about the spindle 28.

The operation of the device is as follows: Assuming it has been mounted on a mixer 30 so that the wheel 33 may be rotated, it is only necessary to place the blade 47 being sharpened within the slot 45. In doing so the guard 55 is moved out of the way manually until the blade 47 is in position with one face of its cutting edge against the grinding face 34. The guard 55 is now released and the blade 47 is held against the wheel by the spring 60. The blade 47 is then drawn through the slot 45 and then through the slot 46 in the same manner.

It can be seen from the foregoing that a blade passing through this grinder must be sharpened correctly since the angularity and pressure are controlled by the machine itself.

We claim:

A knife sharpener comprising a body having end walls and a transverse intermediate wall, a spindle journaled in the top of one end wall and said intermediate wall, a grinding wheel mounted on said spindle, said wheel having bevelled sides, a cap over said body forming a guard for said wheel, said cap having inclined slots on opposite sides of said wheel cutting through said cap, a cover plate on the front of said body, a pair of knife guards hinged within said cover plate and extending upwardly there from, a spring for urging said guards toward said wheel, one edge of one of said guards adapted to engage the outer side of a knife blade and means for resisting the rotation of said body around the axis of said spindle.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 525,414 Ginn Sept. 4, 1894 961,554 Sweet June 14, 1910 1,286,948 Crocker Dec. 10, 1918 1,726,571 Kelley Sept. 3, 1929 2,257,407 Wulff Sept. 30, 1941 2,431,939 Johnson Dec. 2, 1947 2,464,660 White Mar. 15, 1949 2,566,809 Risley et a1 Sept. 4, 1951 2,573,377 Wolbaum Oct. 30, 1951 FOREIGN PATENTS Number Country Date 569,539 Germany Feb. 3, 1933 981,178 France Jan. 10. 1951 

